docs: def _get_redis_connection():
      """
      Return a Redis connection based on the Flask application's configuration.
  
      The connection parameters are retrieved from `REDIS_URL` configuration
      variable.
  
      :return: an instance of :class:`redis.Connection`
      """
      url = current_app.config.get('REDIS_URL', 'redis://localhost:6379')
      return redis.from_url(url, decode_responses=True)